content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable.internal.operators;
  
  import static org.junit.Assert.assertSame;
  
  import org.junit.Test;
  
  import io.reactivex.common.functions.Function;
  import io.reactivex.observable.*;
  import io.reactivex.observable.extensions.HasUpstreamSingleSource;
  import io.reactivex.observable.subjects.PublishSubject;
  
  public class MaybeFromSingleTest {
      @Test(expected = NullPointerException.class)
      public void fromSingleNull() {
          Maybe.fromSingle(null);
      }
  
      @Test
      public void fromSingle() {
          Maybe.fromSingle(Single.just(1))
              .test()
              .assertResult(1);
      }
  
      @Test
      public void fromSingleThrows() {
          Maybe.fromSingle(Single.error(new UnsupportedOperationException()))
              .test()
              .assertFailure(UnsupportedOperationException.class);
      }
  
      @Test
      public void source() {
          Single<Integer> c = Single.never();
  
          assertSame(c, ((HasUpstreamSingleSource<?>)Maybe.fromSingle(c)).source());
      }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(Maybe.fromSingle(PublishSubject.create().singleOrError()));
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeSingleToMaybe(new Function<Single<Object>, MaybeSource<Object>>() {
              @Override
              public MaybeSource<Object> apply(Single<Object> v) throws Exception {
                  return Maybe.fromSingle(v);
              }
          });
      }
  }
  